JP2005281516A - Polycarbonate sheet improved with chemical resistance and dummy can consisting of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dummy can excellent in chemical resistance, transparency, mechanical strength and thermal process aptitude. <P>SOLUTION: This polycarbonate sheet is provided by consisting of 65-99 wt. % polycarbonate-based resin having 15,000-30,000 molecular weight and 35-1 wt. % polybutylene terephthalate resin having 1.4-3.4 relative viscosity and finely dispersing the polybutylene terephthalate resin in a matrix of the polycarbonate-based resin by ≤500 nm size, and is obtained by rapidly cooling the molten state polymer to obtain the sheet and then crystallizing the finely dispersed polybutylene terephthalate under a specific condition so as to make ≤10 % sheet haze. And the dummy can is obtained from the sheet. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a polycarbonate sheet excellent in chemical resistance, transparency and mechanical properties, and a dummy can made thereof.

  In the vending machine, a sample sample having the same shape as the product is displayed on the purchase button so that the product to be purchased can be easily understood. In the past, actual products with extracted contents were often displayed, but in order to increase the display effect, plastic dummy cans that can be illuminated from the inside are often used. I came. If it is a can with a simple shape, it is only necessary to insert a sheet or film printed with the same design as the product into the holder so that it is semicylindrical, but in the case of a can with an uneven shape or a plastic bottle In order to reproduce complex shapes, direct blow bottles and thermoformed containers must be used.

  Recently, beverages in plastic bottles are increasingly sold at vending machines, but because of their complicated shape, bottles were made by direct blow and printed patterns were displayed on shrink film. Things were used. However, dummy cans need to be replaced in the case of seasonal replacement of products or new product launches. With the recent shortening of the product life cycle, heat that can be produced at low cost instead of expensive direct blow bottles. There has been a demand for molded articles.

  The dummy cans displayed in the vending machine are required to be not deformed at about 90 ° C. because they are exposed to direct sunlight in a transparent case. In addition, since the printed surface of the molded product is glossy to improve the display effect of the molded product, high transparency of the material is required. Furthermore, it has a complicated shape in the mating part and the like, and excellent thermoforming workability is also required. In addition, it is necessary that no solvent cracks occur due to the solvent during printing, and that the printed ink is adhered with sufficient strength even when stretched at a high magnification by thermoforming.

  Thus, the required performance required for the dummy can is high, and thermoformed products made of various materials have been studied. However, we have not found an optimal thermoforming material that can meet all the required performance. Currently, the backside is printed on a polycarbonate sheet with excellent transparency and high heat resistance, and thermoforming. Often molded products are used.

  However, since polycarbonate is inferior in chemical resistance, blocking is likely to occur after printing and defects are likely to occur. Further, solvent cracks occur due to the solvent contained in the ink, and the impact strength of the molded product is extremely reduced. There was a problem and there was a strong need for improvement.

  In view of this, it has been considered to use polyester blended with polycarbonate having good chemical resistance. For example, chemical resistance is greatly improved by blending polybutylene terephthalate with polycarbonate (Patent Document 1). However, at the time of polycarbonate sheet production, it is not possible to obtain a sheet with good transparency simply by adding polybutylene terephthalate as a raw material, and the transparency is greatly reduced even by thermoforming. It cannot be used for dummy cans.

It is known that polycarbonate and polyethylene terephthalate have a non-oriented refractive index close to each other, so that a relatively transparent sheet can be obtained when melt blended (Patent Document 2). However, in this method, when the film is stretched by thermoforming, the refractive index changes due to orientation, so that the transparency is extremely lowered and cannot be used for a dummy can. In addition, a method of improving the refractive index of polyester by introducing a copolymer component and using a polymer closer to polycarbonate has been studied (Patent Document 3). As a result, it is known that when the degree of orientation is low, it is almost transparent. However, it has been found that when the film is subjected to high stretching like a dummy can, it causes a significant decrease in transparency and is almost ineffective.

Polyester-polyester transesterified polymers are also being considered, but transesterified polymers are not only expensive, but also have a glass transition temperature between polycarbonate and polyester, making them heat resistant for use in dummy cans. It has a drawback that the property is insufficient (Patent Document 4).
JP-A-48-54160 Japanese Patent Publication No. 36-14035 JP 2000-103948 A JP 09-216941 A

  As a result of intensive studies to solve such conventional problems, the present inventors have reached the present invention, and the object is excellent in chemical resistance, transparency, and mechanical properties. The object is to obtain a polycarbonate sheet and a dummy can for a vending machine comprising the same.

The above object is a sheet in which a polybutylene terephthalate resin is finely dispersed in a polycarbonate resin matrix with a size of 500 nm or less, and the molten polymer is rapidly cooled so that the sheet haze is 10% or less. By printing and thermoforming a polycarbonate sheet characterized in that the polybutylene terephthalate finely dispersed satisfies the condition of the following formula (1), and a laminate thereof: Achieved by the resulting vending machine dummy.

(1) Formula ΔHc <0.2ΔHm

ΔHc: heat of crystallization of polybutylene terephthalate ΔHm: heat of crystallization melting of polybutylene terephthalate

  The sheet and dummy can of the present invention are not only excellent in heat resistance, transparency and mechanical properties, but also excellent in printing processing, thermoformability, recyclability and economy, and are optimal for vending machines.

The polycarbonate used in the present invention preferably has bisphenol A as the main dihydric phenol unit, but may contain a dihydric phenol unit other than bisphenol A within a range not impairing the effects of the present invention. Examples of dihydric phenol units other than bisphenol A include hydroquinone, 4,4′-dihydroxydiphenyl, bis (4-hydroxyphenyl) cycloalkane, bis (4-hydroxyphenyl sulfide, bis- (4-hydroxyphenyl) -sulfone. (Hereinafter abbreviated as “bisphenol S”), a compound such as bis (4-hydroxyphenyl) sulfoxide, bis (4-hydroxyphenyl) ether, or (3,5-dibromo-4-hydroxyphenylpropane, bis (3,5 -Hydrogenated bisphenols such as (dichloro-4-hydroxyphenyl) propane, and these dihydric phenol units may be used alone or in combination of two or more. Polyfunctional aromatic compounds and dihydric phenols And / or thermoplastic random branched polycarbonate reacted with a carbonate precursor.

  The molecular weight of the polycarbonate resin used in the present invention is usually preferably 15,000 to 30000, particularly preferably 18000 to 26000 as a viscosity average molecular weight calculated from the solution viscosity measured at 25 ° C. in a methylene chloride solvent. When the viscosity average molecular weight is less than 15,000, the impact strength of the sheet is lowered, which is not preferable. On the other hand, when it exceeds 30000, the melt viscosity of the resin becomes high, which makes it difficult to extrude, which is not preferable.

  The relative viscosity of the polybutylene terephthalate resin used in the present invention is required to be 1.4 to 3.4 as measured in a phenol / tetrachloroethane mixed solvent having a measurement temperature of 20 ° C. and a weight ratio of 60/40. . If it is less than 1.4, the melt viscosity at the time of extrusion is too low, so that not only is it difficult to finely disperse it in the polycarbonate matrix, but it is also easy to crystallize, so the thickness at which a transparent sheet is obtained by rapid cooling becomes small Therefore, it is not preferable.

  The polybutylene terephthalate used in the present invention is preferably a polybutylene terephthalate homopolymer from the viewpoint of economy and transparency. However, as long as the effects of the present invention are not impaired, dicarboxylic acid components such as isophthalic acid, adipic acid, diphenyl carboxylic acid, diphenyl ether dicarboxylic acid, diphenyl sulfone dicarboxylic acid, sebacic acid, naphthalenedicarboxylic acid, diethylene glycol, hexamethylene glycol In addition, glycol components such as trimethylene glycol, propylene glycol, cyclohexanedimethanol, neopentyl glycol, butylene glycol can be copolymerized. From the viewpoint of change in refractive index due to copolymerization and decrease in crystallinity, it is preferably 15 mol% or less.

In addition, a polyester-based resin can be blended as long as the effects of the present invention are not impaired. Examples thereof include homopolyester, cyclohexanedimethanol copolymer polyester, polyethylene naphthalate copolymer polyester, neopentyl glycol copolymer polyester, and isophthalic acid copolymer polyester. These polyesters are compatible with polybutylene terephthalate at the molecular chain level in the amorphous state, but the crystals are separated into individual resins, so that the crystallization speed is controlled and the crystal size is reduced. You can also By blending about 5 to 35 parts by weight of a polyester-based resin with respect to 100 parts by weight of polybutylene terephthalate, it is possible not only to prevent deterioration of sheet haze during film formation, but also polybutylene terephthalate in a state dispersed in a polycarbonate matrix. Since the effect of reducing the spherulite size in the resin is seen, the transparency of the thermoformed product can also be improved. However, if it exceeds 35 parts by weight, care must be taken because the transparency of the thermoformed product is reduced.
The thickness of the product of the present invention needs to be 10 to 600 microns. In order to rapidly cool the polybutylene terephthalate in the polycarbonate matrix, the thickness of the sheet needs to be in the above range. Preferably they are 15 microns or more and 550 microns or less, More preferably, they are 30 microns or more and 500 microns or less. When it exceeds 600 microns, the cooling efficiency by the cooling roll is lowered, so that it is difficult to rapidly cool polybutylene terephthalate, and the transparency of the laminate is lowered. On the other hand, when the thickness of the sheet is smaller than 10 microns, the sheet itself is insufficient in rigidity, so that the heat resistance of the sheet and the thermoformed product is insufficient, which is not practical.

  Moreover, as long as the effect of the present invention is not impaired, the thickener, the crosslinking agent, the heat stabilizer, the fluidity improver, the ultraviolet absorber, the antistatic agent, and the antifogging are within the range not deteriorating the transparency of the sheet. An agent or the like can be added. Further, when matting is required, a colorant such as titanium dioxide, calcium carbonate, iron oxide, carbon black, etc. can be contained.

  The product of the present invention is required to be 65 to 99% by weight of a polycarbonate resin having a molecular weight of 15000 to 30000 and 35 to 1% by weight of a polybutylene terephthalate resin having an intrinsic viscosity of 1.4 to 3.4, preferably a polycarbonate resin It consists of 75 to 98% by weight of resin, 25 to 2% by weight of polybutylene terephthalate resin, particularly preferably 80 to 97% by weight of polycarbonate-based resin, and 20 to 3% by weight of polybutylene terephthalate resin.

  In the product of the present invention, it is necessary that the polybutylene terephthalate resin is finely dispersed in a polycarbonate resin matrix with a size of 500 nm or less. A particularly preferable fine dispersion size is not more than the visible light wavelength region and not more than 400 nm. The smaller the size of the dispersion, the better the smaller the resin is in the transesterification reaction. When the dispersion size of polybutylene terephthalate exceeds 500 nm, the transparency of the laminate and the thermoformed product is lowered, which is not preferable. Further, it is necessary that the polybutylene terephthalate is finely dispersed in the polycarbonate resin matrix, specifically, the polycarbonate resin is in a continuous phase and the polybutylene terephthalate resin is in a dispersed phase. This is because when polybutylene terephthalate forms a continuous phase, not only the haze is lowered, but also the crystal temperature of the polybutylene terephthalate that is crystallized needs to be increased, and the thermoformability is greatly reduced. .

  Polycarbonate-based resin and polybutylene terephthalate resin have relatively good compatibility. Polybutylene terephthalate resin is added to polycarbonate resin only by blending polycarbonate and polybutylene terephthalate having a specific range of molecular weight and intrinsic viscosity at a specific ratio. Can be finely dispersed to 500 nm or less. In order to more uniformly and finely disperse, it is also effective to bring both melt viscosities as close as possible, to knead in advance before film formation, or to use a twin screw extruder for the film forming machine, Particularly important is that the amount of polybutylene terephthalate is within the scope of the present invention.

  If the amount of the polybutylene terephthalate resin finely dispersed in the polycarbonate-based resin exceeds 35% by weight, it becomes difficult to uniformly and finely disperse the resin in the polycarbonate matrix with a size of 500 nm or less by adjusting the melt viscosity or by devising the kneading method. The transparency of the sheet and the thermoformed product is not preferable. On the other hand, when the content is less than 1% by weight, the effect of improving the chemical resistance of polycarbonate by blending polybutylene terephthalate is low, and problems such as blocking and solvent cracking occur when printing on a sheet, which is not preferable.

  In addition, it is necessary to obtain a sheet by rapidly cooling the molten polymer so that the sheet haze in the product of the present invention is 10% or less. In order to reduce the sheet haze to 10% or less, it is necessary to rapidly cool the molten polymer extruded from a T die or the like at a roll temperature of preferably 10 to 50 ° C, more preferably 10 to 30 ° C. The polybutylene terephthalate resin used for the layer (B) has a high crystallization rate, and at the roll cooling temperature usually used when producing a polycarbonate sheet, it is crystallized directly from the molten state, resulting in a crystal size exceeding the wavelength of visible light. , Sheet haze is greatly reduced, which is not preferable. On the other hand, when it is once cooled and then crystallized again, polybutylene terephthalate microcrystals smaller than the wavelength of visible light are generated, so the sheet haze does not decrease.

In addition, when polybutylene terephthalate finely dispersed in a polycarbonate matrix is measured according to JIS-K-7122 using a differential scanning calorimeter (DSC), the condition of the following formula (1) is satisfied. It is necessary to crystallize.

(1) Formula ΔHc <0.2ΔHm

ΔHc: heat of crystallization of polybutylene terephthalate ΔHm: heat of crystallization melting of polybutylene terephthalate

When ΔHc is smaller than 0.2ΔHm, when the laminate is thermoformed, only the polycarbonate is plastically deformed, and the polybutylene terephthalate finely dispersed in the crystallized state changes the refractive index due to orientation and the size of the dispersion. Since there is no change, there is no decrease in transparency of the container during thermoforming. When ΔHc is 0.2ΔHm or more, the polybutylene terephthalate is insufficiently crystallized, and the polybutylene terephthalate undergoes stretching during thermoforming, so that the refractive index changes greatly. Since the difference is increased and the average dispersion size of the polybutylene terephthalate is further increased by stretching, the transparency of the thermoformed product is lowered, which is not preferable.

  In order to reduce ΔHc to 0.2ΔHm or less, it is important that the copolymerization ratio is low and the transesterification reaction with other polymers is suppressed as much as possible. When the transesterification proceeds and the crystallization speed decreases, the transparency of the laminate and the molded article decreases because the size of the crystal that has been recrystallized after being rapidly cooled once becomes larger than the wavelength of visible light. . Polybutylene terephthalate has a glass transition temperature near room temperature and an extremely fast crystallization rate. Therefore, when a homopolymer is used, ΔHc is 0.2ΔHm or more without special heating after rapid film formation. However, caution must be exercised because the crystallization rate becomes slow when the copolymer has been copolymerized or when the transesterification reaction has partially proceeded in response to a thermal history. In order to reduce ΔHc, it is also effective to promote crystallization by heating the quenched sheet to a temperature equal to or higher than the crystallization temperature of polybutylene terephthalate or by aging. In some cases, there is no problem in crystallization within the heating time immediately before stretching during thermoforming.

  Dummy cans need ink adhesion suitability with good adhesion strength even after thermoforming, and anti-stacking properties for improving workability during display work, as long as the effects of the invention are not hindered. If present, there is no problem in blending an anti-stacking agent or an additive having a releasing effect. In addition, since they are displayed in the vending machine for a long time and receive ultraviolet rays, there is no problem in blending ultraviolet absorbers and light stabilizers, or other heat stabilizers, fluidity improvers and the like.

  The thickness of the dummy can of the present invention is not particularly limited, but can usually be obtained by thermoforming a sheet having a total thickness of 150 to 600 μm. The laminate can be obtained, for example, by performing melt extrusion with an ordinary polyester extruder such as a single screw extruder or a twin screw vent type extruder and cooling the molten resin with a cooling drum. The sheet is preferably cooled as quickly as possible in order to prevent deterioration of transparency and thermal adhesiveness due to crystallization, and haze is required to be 10% or less, preferably 7% or less, more preferably 5% or less. .

  As the sheet, a known extrusion apparatus having a feed block die, a multi-manifold die, or the like can be used. Moreover, it can manufacture by well-known techniques, such as melt lamination and dry lamination.

  In addition, as a film forming method, there are a method of cooling by sandwiching between metal rolls (touch roll method), an electrostatic application method, an air knife method, and the like. The method is preferred.

  In addition, when the dummy can is displayed in a vending machine, antistatic performance is required so that dust does not easily adhere to it, so there is no particular problem with applying an antistatic agent when manufacturing a sheet. As the antistatic agent, a known one can be used, but it is effective to use a cationic polymer type from the viewpoint of performance and durability.

  In general, in-line recycling is used to pulverize the ears and skeleton parts punched from thermoformed containers that are produced when the sheet is formed into a sheet, and return the raw material as a raw material. There is no problem even if it is blended as long as it has the characteristics and does not extremely deteriorate the physical properties.

  There is no problem in printing on the product of the present invention by a method generally performed with a dummy can. In general, solvent-based ink is often used because it requires ink having good adhesion and a printed portion that expands during thermoforming, but a UV curable type can also be used depending on the application. As a printing method, silk screen printing is generally used in many cases, but gravure, offset, flexographic printing, and the like can also be used. In general, the back side printing with good gloss of the molded product is performed, but depending on the case, front side printing is also possible.

  The product of the present invention may use any method such as vacuum forming, pressure forming, hot plate forming, plug assist forming, reverse draw forming, air slip forming, or a combination of these methods.

EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to this. Each characteristic value was measured according to the following method.
(1) Relative viscosity of polybutylene terephthalate resin It was measured in a phenol / tetrachloroethane mixed solvent having a weight ratio of 60/40 at a concentration of 1.0 g / dl at 20 ° C.
(2) Molecular weight of polycarbonate resin It was calculated | required as a viscosity average molecular weight converted from the solution viscosity measured at 25 degreeC in the methylene chloride solvent.
(3) Haze of sheet The haze (cloudiness value) of the sheet was measured by a method according to JIS-K-7105 using NDH-20D manufactured by Nippon Denshoku Co., Ltd. A haze value of less than 3.5%
Those with 3.5% or more and less than 6%
Those with 6.0% or more were evaluated as x.
(4) Dispersion size measurement of polybutylene terephthalate in polycarbonate The cut surface of the sheet was stained with ruthenium oxide (RuO ₄ ) and observed at 20000 times using a transmission electron microscope. The dispersion size was measured from the obtained image, and the average dispersion size was determined.
(5) ΔHc, ΔHm
Measurement was performed by a method according to JIS-K-7105 using a differential differential calorimeter (model DSC-7) manufactured by PerkinElmer. Measurement was performed in a nitrogen stream at a temperature rising rate of 10 ° C./min to obtain ΔHc and ΔHm.
(6) Ink adhesion suitability Adhesion is determined by putting a crosscut (100 pcs / cm ² ) on the printed surface and pasting cello tape (registered trademark): CT-24 manufactured by Nichiban Co., Ltd. at 45 ° to the crosscut surface. Using a hand roller, the pressure was reciprocated 10 times with a load of about 5 kg, cellotape (registered trademark) was forcibly peeled in the 180 ° direction, and the degree of peeling of the coating layer was observed and evaluated.
Judgment criteria are those without peeling.
Those with less than 5 peels
The number of peeled pieces is 5 or more and less than 10 △
What peeled 10 or more was made into x.
(7) Occurrence of solvent cracking by ink The sheet after printing and drying was observed with a microscope, and the case where no crack was observed was evaluated as ◯, and the case where even a slight crack was observed was evaluated as ×.
(8) Design shift at the time of thermoforming The design shift of the thermoformed product was evaluated, and a product with a shift of 3 mm or more from the predetermined position was rejected. The failure rate is
○ less than 2%
△ 2% or more and less than 5%
The thing which generate | occur | produced 5% or more was evaluated as x.
(9) Thermoforming condition width A dummy can obtained by thermoforming was sandwiched between fixed holders, and it was confirmed whether the mating portion was accurately thermoformed. The thermoforming condition width (the sheet surface temperature at the time of thermoforming was measured with an infrared thermometer) that can accurately reproduce the fitting portion was evaluated.
Appropriate thermoforming condition width is 10 ℃ or more ○
△ less than 10 ℃
Those without proper conditions were evaluated as x.
(10) Decrease in transparency due to thermoforming A transparent part of a molded product and a part having a draw ratio of 2 times or more were cut out and the haze was measured. X in which haze is reduced by 10% or more in comparison with haze before stretching
△ 5% or more and less than 10% haze drop
The evaluation was made with ○ less than 5%.
(11) Heat resistance of molded product The dummy can was left in a 90 ° C. environment for 5 hours, and then left in a 20 ° C. environment for 5 hours. This heating and cooling is repeated 10 times, the degree of deformation is visually evaluated, and no deformation is observed.
Even a slight deformation was indicated as x.
(12) Impact resistance of molded product After printing and thermoforming, evaluation was performed based on a crack generation rate in a punching process in which dummy cans were separated one by one.
Those with an incidence of cracking of less than 0.1%
Those with 0.1% or more were marked with ×.
(13) Transparency of the molded product A transparent portion of the molded product and a portion having a draw ratio of 2 times or more are cut out, and the haze is measured.
A haze value of less than 10%
10% or more and less than 15%
Evaluation was made with x of 15% or more.
(14) Overall evaluation ○ ○
△ If there is even one
Those having at least one x were evaluated as x.

Melt extrusion was performed from a T die under the conditions of a set temperature of 280 ° C. and a vacuum degree of 667 Pa in the vent portion of the twin screw extruder. The ears of the sheet cut to obtain a sheet with a predetermined width were returned to the core layer (11 to 14 wt% by weight). The melt-extruded resin was cooled at the roll temperature described in the examples by a touch roll method to obtain sheets having various configurations. In addition, in order to impart antistatic performance to the laminate during film formation, an antistatic agent (trade name: Julimer SPO-600) manufactured by Nippon Pure Chemical Co., Ltd. is made into an aqueous solution with a concentration of 5 wt%, and the sheet is not printed. About 1 ml / m ^{2 was} uniformly applied to the surface, and then dried with a dryer.

In order to print the pattern of the dummy can on the obtained sheet, silk screen printing was performed using EG ink manufactured by Teikoku Ink Manufacturing Co., Ltd. The obtained printed laminate was thermoformed into a 500 ml plastic bottle type dummy can having a length of about 210 mm, a width of about 67 mm, and a depth of about 35 mm using a vacuum / pressure forming machine with a plug assist. (Thermoforming conditions: heater set temperature 350 ° C., mold temperature 60 ° C., vacuum 8000 Pa).
Examples 1-18, Comparative Examples 1-14
Sheets having various configurations described in Tables 4 to 6 were formed using the resins described in Tables 1 to 3. The obtained sheet was printed and thermoformed to produce a dummy can, and various physical properties were evaluated.

In Table 4, although it evaluated about the composition of resin, when there are few compounding quantities of the polybutylene terephthalate to mix | blend, it turns out that the improvement effect of chemical resistance is small. On the other hand, when it mix | blends exceeding a regulation range, it turns out that the transparency of a thermoformed product falls significantly. In addition, since the polybutylene terephthalate to be blended is copolymerized or the like, if the crystallization rate is too slow, ΔHc / ΔHm exceeds 0.2, and it can be seen that the transparency is rapidly lowered by thermoforming. . It can also be seen that the transparency of the thermoformed product varies greatly depending on the dispersion size of the polybutylene terephthalate finely dispersed in the polycarbonate matrix.

Table 5 shows an example in which the crystallization state of polybutylene terephthalate blended in the polycarbonate matrix is different, but when the thickness of the sheet is thick, it cannot be rapidly cooled even if the roll temperature is lowered during film formation, It can be seen that the haze of the sheet decreases because the finely dispersed polybutylene terephthalate crystallizes from the molten state. It can be seen that the haze of the sheet in which polybutylene terephthalate is crystallized from a molten state is further reduced by thermoforming.

    In Table 6, although the state of cooling during film formation is variously changed, it can be seen that the haze of the sheet decreases at a high roll cooling temperature, which is a normal polycarbonate film forming condition. In the product of the present invention, it can be seen that it is necessary to rapidly cool at a low roll temperature.

The polycarbonate sheet of the present invention is excellent in chemical resistance, transparency, mechanical properties and suitability for thermoforming, and the thermoformed product obtained from the sheet is optimal for a dummy can for a vending machine.

Claims (3)

It consists of 65 to 99% by weight of a polycarbonate resin having a molecular weight of 15000 to 30000, 35 to 1% by weight of a polybutylene terephthalate resin having a relative viscosity of 1.4 to 3.4, and the polybutylene terephthalate resin is 500 nm in the matrix of the polycarbonate resin. The sheet is finely dispersed in the following size, and after the molten polymer is rapidly cooled so that the sheet haze is 10% or less to obtain a sheet, the finely dispersed polybutylene terephthalate is represented by the following (1). A polycarbonate sheet characterized by satisfying the condition of the formula (1) Formula ΔHc <0.2ΔHm
ΔHc: heat of crystallization of polybutylene terephthalate ΔHm: heat of crystallization melting of polybutylene terephthalate       The sheet according to claim 1, wherein the thickness is 10 to 600 microns. A dummy can obtained by printing and thermoforming the sheet of claim 1 or 2.